Daylight-harvesting systems that redirect sunlight into building cores have been utilized to provide interior lighting for many years. However, it has proved difficult to supplement the harvested sunlight, e.g., during night or periods of inclement weather, with other sources of illumination without interfering with the efficient transfer of the sunlight into the interior space and/or consuming valuable “real estate” from which the sunlight shines into such spaces. Similarly, the illumination of objects such as artwork and jewelry in display cases is often made difficult by the viewer casting shadows on the objects. In some situations where lighting internal to a display case is used, frames for the case may be bulky, or dimensions of the case may not be ideal for optimum viewing.
Various conventional systems for such applications incorporate linear fluorescent lighting when, e.g., there is insufficient daylight to illuminate an office space. However, linear fluorescent lamps typically have a toroidal luminous intensity distribution, which requires the light guide in the vicinity of the lamps to be lined with an opaque reflective material in order to efficiently couple the emitted light to the diffusers and into the illuminated office space below. Such coatings may compromise the overall efficiency of the illumination system, particularly the sunlight-harvesting portion. Thus, there is a need for efficient hybrid illumination systems that improve upon conventional daylight-harvesting systems, as well as systems utilized for other illumination and/or display applications.